This invention relates to a posturized bedding or seating product in which certain sections are firmer than other sections of the product.
Conventional bedding or seating products have a spring core made of a plurality of coil springs arranged into a matrix of rows and columns of coil springs. Each of the coil springs has an upper end turn and a lower end turn, with a plurality of central convolutions therebetween. The diameter of the end turns may be identical to the diameter of the central convolutions of the spring. Alternatively, the end turns of the coil springs may be of a larger or smaller diameter than the central convolutions of the springs. Typically, the coil springs are of the same height for ease of assembly. The coil springs are connected by securing the end turns of adjacent springs to each other.
The end turns of adjacent coil springs are most commonly clipped together or secured together with helical lacing wires. Such helical lacing wires encircle the end turns of adjacent coil springs, thus securing the end turns together and hence preventing the coil springs from separating from one another. Encircling the upper and lower end turns of all of the coil springs with such helical lacing wires creates a unitary spring core which is covered with padding and wrapped in an upholstered material. Such spring cores have a uniform relatively firm feel across the entire upper surface of the product due to the end turns of the coil springs being secured to each other.
In order to impart a softer, more resilient feel to the bedding or seating product, the spring cores of such products have been modified to change the location of the helical lacing wires connecting the coil springs of the spring core. U.S. Pat. Nos. 2,480,158 and 5,713,088 disclose spring cores comprising a plurality of aligned coil springs joined together with helical lacing wires, the helical lacing wires being spaced below the upper end turns of the coil springs. As a result, the sections of the coil springs located above the helical lacing wires provide an increased flexibility at the upper ends of the coil springs, thus imparting a softer feel to the upper surface of the bedding or seating product.
U.S. Pat. No. 5,713,088 discloses a spring core in which helical lacing wires are spaced below the upper end turns of the coil springs and above the lower end turns of the coil springs so as to create a two-sided mattress with a xe2x80x9csoftxe2x80x9d feel on both surfaces of the mattress. Such a mattress is considered a xe2x80x9ctwo-sidedxe2x80x9d mattress because it has an identical feel on both sides.
Although each of these patents discloses a spring core in which the helical lacing wires or connectors are inwardly spaced from the terminal end convolutions of the coil springs to impart a softer feel to at least one surface of the bedding or seating product in which the spring core is used, these products are not posturized, i.e., they have a uniform feel across the entire upper surface thereof.
Consequently, it has been one objective of the present invention to provide a posturized bedding or seating product utilizing springs of differing heights so as to impart differing degrees of firmness to different sections of the product.
It has been a further objective of the present invention to provide a bedding or seating product having a spring core of rows and columns of coil springs connected by helical lacing wires spaced below the upper end turns of select coil springs.
It has been a further objective of the present invention to provide a posturized bedding or seating product in which filler material is placed between groups of springs, the filler material resting upon the upper end turns of other groups of springs.
The invention of this application which accomplishes these objectives comprises a bedding or seating product which is posturized so as to impart different degrees of firmness to different sections of the product.
The bedding or seating product comprises a spring core, filler located above at least one section of the spring core, and an upholstered covering surrounding the filler and the spring core.
The spring core comprises a plurality of coil springs arranged in transversely extending rows and longitudinally extending columns. Each of the coil springs has an upper end turn, a lower end turn and a plurality of central convolutions between the end turns. The spring core is divided into sections, each of the sections comprising a plurality of coil springs of an identical height. The coil springs of at least one of the sections are of a first height which, for purposes of this application will be considered short coil springs. The coil springs of at least one of the sections comprises coil springs of a second height greater than the first height, which, for the purposes of this application will be considered tall coil springs.
In one preferred embodiment of the present invention, the spring core is divided into multiple sections, each section having several transversely extending rows of identical coil springs of the same height. At least one of these sections comprises coil springs of a first height and at least one other section comprises coil springs of a second height greater than the first height. Filler is located above the sections of coil springs of a first height. The filler imparts a softer feel to the user than does the end turns of the coil springs of a second height. Consequently the sections comprising rows of short coil springs (those of a first height) and filler above such springs are of a lesser firmness than the firmness of the other sections comprising rows of tall coil springs (those of a second height).
In several preferred embodiments of the present invention, the filler is of a third height so that when placed upon the springs of a first height, the sum of the first and third heights is approximately equal to the height of the tall springs, i.e., the second height. In such a manner, the bedding or seating product has a uniform upper surface comprising the upper end turns of the tall coil springs and the upper surface of the filler.
The filler may be numerous structures and/or materials, including but not limited to pieces of urethane foam, various fibrous materials, air bladders or water bladders or even matrixes of short springs contained in cloth fiber pockets.
In another preferred embodiment of the present invention, the sections may extend from head to foot rather than from side to side. In this preferred embodiment, each section comprises a plurality of longitudinally extending columns of coil springs of an identical height.
In one preferred embodiment of the present invention, the coil springs are joined together with helical lacing wires. Upper helical lacing wires encircle the upper end turns of the short coil springs and intermediate convolutions of the tall coil springs. In this preferred embodiment, lower helical lacing wires encircle the lower end turns of all of the coil springs. The lower end turns of all of the coil springs are in a generally horizontal plane and define the bottom surface of the bedding or seating product.
In another preferred embodiment the tall coil springs of a second height extend above and below the end turns of the short springs of the spring core. In this embodiment upper and lower helical lacing wires encircle the upper and lower end turns of the short coil springs, respectively and intermediate convolutions of the tall coil springs. In this embodiment, filler is located both above and below the short coil springs. The upper and lower surfaces of the filler are generally coplanar with upper and lower end turns of the tall coil springs, respectively.
In another preferred embodiment of the present invention, tall coil springs are arranged in a generally rectangular pattern in the middle of the bedding or seating product, and short coil springs (springs of a lesser height than the springs in the middle of the product) are arranged around the perimeter of the generally rectangular section of tall coil springs. Filler is placed above the short coil springs around the perimeter of the bedding or seating product in order to provide a softer feel to the user around the perimeter than in center of this embodiment of product.
In another preferred embodiment of the present invention, a section of short coil springs are arranged in a generally rectangular pattern in the middle of the bedding or seating product. Tall coil springs (springs of a greater height than the springs in the middle section of the product) are arranged around the perimeter of the generally rectangular section of short coil springs. Filler is placed above the short coil springs in the middle of the bedding or seating product. The tall springs provide an edge support around the perimeter of the product which is of a greater firmness than the central section or core of the product.